CVE-2026-43499
Description
In the Linux kernel, the following vulnerability has been resolved: rtmutex: Use waiter::task instead of current in remove_waiter() remove_waiter() is used by the slowlock paths, but it is also used for proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from futex_requeue(). In the latter case waiter::task is not current, but remove_waiter() operates on current for the dequeue operation. That results in several problems: 1) the rbtree dequeue happens without waiter::task::pi_lock being held 2) the waiter task's pi_blocked_on state is not cleared, which leaves a dangling pointer primed for UAF around. 3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter task Use waiter::task instead of current in all related operations in remove_waiter() to cure those problems. [ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the changelog ]
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | affected | |
| debian | bullseye | affected | |
| debian | forky | fixed | 7.0.4-1 |
| debian | sid | fixed | 7.0.4-1 |
| debian | trixie | fixed | 6.12.86-1 |
| windows | affected | |
References
- https://git.kernel.org/stable/c/3bfdc63936dd4773109b7b8c280c0f3b5ae7d349
- https://git.kernel.org/stable/c/3fb7394a837740770f0d6b4b30567e60786a63f2
- https://git.kernel.org/stable/c/6d52dfcb2a5db86e346cf51f8fcf2071b8085166
- https://git.kernel.org/stable/c/88614876370aac8ad1050ad785a4c095ba17ac11
- https://git.kernel.org/stable/c/8a1fc8d698ac5e5916e3082a0f74450d71f9611f
- https://www.suse.com/security/cve/CVE-2026-43499.html
- https://security-tracker.debian.org/tracker/CVE-2026-43499
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-43499
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.